WALNUT  Charles Jock is a nice, polite, respectful guy. He has a great story, trudging across deserts with his family when he was 3 to escape the bloody conflict in what has since become South Sudan, ending up in San Diego and becoming a favorite to represent the United States at the 2012 Olympics.

And he’s fast, with a series of blazing workouts in recent weeks at UC Irvine, where he is a senior.

But this is track and field. This is the 800 meters.

Nice guys sometimes finish fifth.

“I’m a little disappointed,” Jock said Saturday. “I expected to run a lot faster. Definitely a little surprised.”

It was a day at the 54th annual Mt. San Antonio Relays – one of the first major U.S. meets of the outdoor season – when several past and future Olympians posted rather impressive marks for April, among them a wind-aided 9.85 seconds by Walter Dix in the 100 meters and a 23-foot, 4½-inch long jump by Brittney Reese that broke a 28-year-old meet record.

Many figured Jock would, too. This was his first 800 meters of a season in which many expect him to become an international star, and it followed weeks of sizzling times in practice and over 400 meters at smaller meets, and there were rumblings he was primed to rip off a personal best and send shivers through the track world, and …

“I felt good until 650 (meters),” Jock said, “and when I tried to go my legs just wouldn’t turn over … I thought I might be able to run a PR today.”

Instead he clocked 1 minute, 47.15 seconds – fifth place in a race won by Duane Solomon in 1:46.03. Jock’s PR: 1:44.67.

Jock planned to run a 50-second opening lap. Instead: 53.5 seconds.

Part of it, to use his word, was rust, having raced over two laps just once since last June (and that was in August). Part, also, might be dragging the burden of expectation around a urethane oval.

“I show up at a track meet and people know who I am,” said Jock, who, as a college junior, was a surprise qualifier for the 2011 World Championships in South Korea. “I walk in and people look at me in a different way. People come up to me and ask me for advice now, which is kind of weird. It’s definitely a lot different.”

Everything else about Jock, though, is bigger and better as well. His strength training, his 400 times, his practice splits, his recovery ability – all ahead of last year at this time. O’Boyle purposely delayed his opening 800 and plans to limit his college races with an eye on June’s Olympic Trials in Eugene, Ore., where the 800 figures to be among the marquee (and most competitive) events.

“I’m confident we’re doing the right things,” O’Boyle, one of track’s most veteran coaches, said. “He’ll be fine.”

A few hours later, Olympic silver medalist Lauryn Williams won the women’s 100 meters in 11.15 seconds. She sat out the 2010 season after realizing “I was just going through the motions,” then returned last year and regularly found herself running 11.4s and finishing last.

But she stuck with it, and the 11.15 is evidence of progress.

“I think I’m a humble person,” Williams said, “but no matter how hard you try you can get humbled in this sport and there’s nothing you can do about it. It’s all about how you come back from it.”

A look at some of the day’s other highlights:

--Dix’s 9.85 would be the fastest time in the world this year had the wind gauge not registered plus-2.4 meters per second, above the allowable 2.0. Did it send a message to the Jamaican sprinters? Dix wouldn’t say, but it should be noted that Puma sponsors this meet and adorned Hilmer Lodge Stadium in green and yellow banners, along with a giant yellow inflatable of “Bolt Arms” (Usain Bolt’s iconic pose) perched atop the press box. Puma also sponsors the Jamaican track team.

--The women’s 100-meter hurdles featured 2004 Olympic gold medalist Joanna Hayes and a two-time world champion Michelle Perry. Perry won, barely, 12.70 seconds to 12.72. Six women in the race were under 13 seconds, including Yvette Lewis, a resident at the Olympic Training Center in Chula Vista.

--Reigning world champion Jason Richardson won the 110 hurdles in 13.20, a meet record and the fastest time in the world this year. Leslie Cole’s 22.63 in the women’s 200 was the second fastest time in the world this year. OTC resident Sean Furey won the javelin at 256-2.

--Allyson Felix, a 200 silver medalist at the last two Olympics, anchored a victorious 4x100 relay. She plans to run the 200 at the U.S. Olympic Trials but says her coach, Bobby Kersee, will decide which other event she’ll enter – the 100 or 400 – a few weeks before. “Unless I don’t like his choice,” Felix said. “Then I’ll veto it.”